Limitation of Simultaneous Analysis of T-Cell Receptor and κ-Deleting Recombination Excision Circles Based on Multiplex Real-Time Polymerase Chain Reaction in Common Variable Immunodeficiency Patients

We used a triplex real-time polymerase chain reaction (PCR) to classify our common variable immunodeficiency (CVID) patients into distinct groups according to the amount of their T-cell receptor excision circles (TRECs) and κ-deleting recombination excision circles (KRECs).TREC and KREC analysis was performed using a multiplex real-time PCR assay. The T- and B-lymphocyte subsets were measured by flow cytometry.The copy number of TRECs and KRECs was significantly reduced in CVID patients compared to healthy controls. The TREC copy number was inversely correlated with age in both healthy subjects and patients; however, the KREC copy number was inversely correlated with age only in CVID patients. Moreover, no association was seen between TREC/KREC copy number and clinical manifestations such as bronchiectasis, splenomegaly, granulomata, autoimmune cytopenias, organ-specific autoimmunity, enteropathy and lymphoid hyperplasia.TREC and KREC quantification might be a useful tool to differentiate between CVID and combined immunodeficiency, but considering the results of this study a classification of CVID patients in certain groups is hardly possible.